The act of thrusting your entire penis forcefully into the vagina at the onset of intercourse causing your partner to yell, "Woooooo" from being surprised. Her response (Wooooo) is paying homage to legendary Professional Wrestler Ric Flair.

When I snuck into my girlfriend's house and gave her the Ric Flair, her "Wooooo" just about woke up her parents.